test(spring-lnurl): add test for SimpleK1FactoryTest

incubator/spring-lnurl/spring-lnurl-auth-simple/src/test/java/org/tbk/lnurl/auth/SimpleK1FactoryTest.java

@@ -0,0 +1,23 @@
+package org.tbk.lnurl.auth;
+
+import org.junit.jupiter.api.RepeatedTest;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+
+class SimpleK1FactoryTest {
+
+    private final SimpleK1Factory sut = new SimpleK1Factory();
+
+    @RepeatedTest(21)
+    void itShouldCreateRandomK1() {
+        K1 firstK1 = this.sut.create();
+        assertThat(firstK1.toArray().length, is(32));
+
+        K1 secondK1 = this.sut.create();
+        assertThat(secondK1.toArray().length, is(32));
+
+        assertThat(firstK1, not(is(secondK1)));
+    }
+}